Device for developing or fixing exposed photographic papers in automatic picture telegraph equipment



Dec. 28, 1965 R. GESELL 3,225,675

DEVICE FOR DEVELOPING 0R FIXING EXPOSED PHOTOGRAPHIC PAPERS IN AUTOMATIC PICTURE TELEGRAPH EQUIPMENT Filed July 15, 1965 IN VEN TOR United States Patent 3,225,676 DEVICE FOR DEVELOPING R FIXING EXPOSED PHOTOGRAPHIC PAPERS IN AUTOMATIC PIC- TURE TELEGRAPH EQUIPMENT Reinhard Gesell, Kiel, Germany, assignor to Dr.-Ing. Rudolf Hell Kommanditgesellschaft, Kiel-Dietrichsdorf, Germany, a German company Filed July 15, 1965, Ser. No. 472,369 1 Claim. (Cl. 95-89) The invention relates to a device for developing or fixing exposed photographic papers in automatic picture telegraph equipment.

After starting and phasing a picture telegraph receiver through the transmitter, the photographic paper to be exposed is taken out from a light-tight supply container, then fixed to the recording drum and is, after the beginning of the picture transmission, exposed pointwise along a narrow helix by means of a recording lamp, the intensity of which is modulated by the received picture signals. After the ending of the recording the exposed photographic paper is unrolled from the drum and lead first through a developing tank and then through a fixing tank. Subsequently, the photographic paper, being still wet, is dryed by application of heat and thereafter it is thrown out into a depositing case. All these procedures do not require any human assistance, rather they are carried out automatically by means of a program control.

Certain difficulties occur in connection with the automatic runoff of the high-speed developing and the highspeed fixing of the photographic papers, both procedures having to be effected within a few seconds. Essentially, the following three conditions are made for said procedures. As the picture telegraph apparatuses, standing on rollers, are sometimes moved to and fro, spilling over of developing or fixing liquid, which is inevitable when using normal bath shells, must be avoided, if possible. As, furthermore, each sheet of photographic paper being developed or fixed, extracts a small quantity of liquid (about 0.06 cu. in.) from the bath and, moreover, the liquid evaporates, the level of liquid drops more and more at each picture in the course of time, so that, in order to process a greater number of pictures (about 200) without permanently filling up liquid and without gradually prolonging the developing time, which is impossible in automatic devices, the photographic paper, for compensation of the sinking level of liquid, must be fed relatively deep into the developing tank, so that a strong bending of the paper is unavoidable, said bending complicating the automatic passing on of the papers. As, finally, a developer which mechanically remains at rest, exhausts in its upper Zones more than in its lower zones and shows different chemical alterations on its surface bordering the air and internally, it must, inorder to maintain its homogeneousness, be frequently stirred up. For this purpose, circulating pumps or stirring devices are required in which the sealing of the driving members passing through the Walls of the developing tank presents diificulties because of attacks by chemical action of the developing and fixing liquids.

According to the invention, all these difliculties are overcome by a hollow body serving as a buffer tank for the liquid, said hollow body being insertable into the developing or fixing tank with only little play between the Walls, being fixable as to height and being provided with a hole or a valve in its bottom and with a short piece of pipe at its top side, an inflatable bag being situated between the bottom of the tank and the bottom of the hollow body, said bag, in inflated condition, sealing the hole or shutting the valve in the bottom of the hollow body and displacing the liquid being located between the bottom of the tank and the bottom of the hollow body, said liquid just filling the tank volume between said bottoms, into the tank volume above the hollow body to such an extent that the liquid flows into the short piece of pipe of the hollow body, thereby filling said hollow body with a quantity of liquid being sufficient for some hundreds of developing and fixing procedures, and said bag, in non-inflated condition, unblocking the hole or opening the valve in the bottom of the hollow body and clearing the tank volume below the hollow body for the liquid flowing back through the open hole or valve and along the side-walls of the tank, until the level of liquid has reached again the level of the bottom of the hollow body.

While the picture to be transmitted is recorded at the receiver, the bag is slowly inflated by means of a pump, the liquid being churned thereby at each picture as a result of its displacement motion and without using additional means. Furthermore, as a result of the buffer action of the hollow body, a constant level of liquid is obtained at each picture, until the reserve of liquid is used up, that being the case after about 200-250 picture developings. After the developing of each picture, the bag is deflated, so that the liquid flows back from the volume above the hollow body and from said body into the tank volume below the hollow body. In the much predominating ,state of rest, i.e. the bag being not inflated, spilling over of the liquid when moving the apparatus and a too rapid evaporation of the liquid are thoroughly avoided by the sealing effect between the hollow body and the walls of the tank, because the surface of the liquid bordering on the air is reduced to the narrow play between the walls. Moreover, the constant level of liquid permits the leading of the photographic papers through the liquid in a slow sweep. Increasing the developing time in the course of time is not necessary.

In a picture telegraph receiver, two equal devices of the kind described, being arranged side by side, are used, the first of which being filled with developing liquid and the second being filled With fixing or stabilizing liquid. The maintenance is reduced to only occasionally cleaning the tanks and filling up the liquids, the moment for said filling up being indicated by a counter or a signal. The developing liquid is warmed up and being kept on constant temperature by means of a heating conductor in connection with a thermostat, said elements being switched on at the start of the apparatus.

For a better understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawing which shows an embodiment of the invention in sectional view.

At the bottom of the plastic tank 1 lies the inflatable, non-extensible plastic bag 2, which is connected with an air pump (not shown) by means of a flexible pipe 3, said pipe being lead along a vertical edge of the tank. The hollow body 4, which can be inserted into the tank 1 with only little play between the walls, is provided with a hole 5 in its bottom and with a short piece of pipe 6 which is open on the top. Instead of the hole 5 likewise a valve can be used which, the bag being in non-inflated condition, is opened by gravity and the bag being in inflated condition, is shut by the rising of the upper part of the bag. As valves are not very reliable when being brought into contact with chemically nonneutral liquids (separation of salt), the use of a simple hole in the bottom of the hollow body and shutting or unblocking said hole by the flexible bag is a constructionally elegant and reliable solution. .The hollow body 4 is resting on projections 7 which are attached to the walls of the tank 1. Upward movements of the hollow body 4 due to the buoyancy of the inflated bag 2 are prevented by a clamping device (not shown) in the cover (not shown) of the tank 1. The photographic papers to be developed or fixed are lead through the liquid by means of a flatly curved guideway 8. The photographic papers 11 are conveyed by the pairs of rolls 9 and 10. The whole quantity of liquid is so dimensioned that it just fills out, the bag 2 being not inflated, the volume between the bottom of the tank and the bottom of the hollow body. The height of the piece of pipe 6 and the volume of the hollow body 4 are so dimensioned that the hollow body can contain, the bag 2 being fully inflated, the quantity of liquid to be consumed for the intended number of developings or fixings. In the course of running the level of liquid within the hollow body drops more and more according to the number of pictures being developed or fixed. Independent of this, the level of liquid constantly remains at the height of the upper opening of the piece of pipe 6.

' Changes and modifications may be made within the scope and spirit of the appended claim.

What I claim is:

i In automatic picture telegraph equipment, a device for developing or fixing exposed photographic papers comprising a hollow body serving as a butler tank for the liquid, said hollow body being insertable into the developing or fixing tank with only little play between the walls, being fixable as to height and being provided with a hole or a valve in its bottom and with a short piece of pipe at its top side, an inflatable bag being situated between the bottom of the tank and the bottom of the hollow body, said bag, in inflated condition, sealing the hole or shutting the valve in the bottom of the hollow body and displacing the liquid being located between the bottom of the tank and the bottom of the hollow body, said liquid just filling the tank volume between said bottoms, into the tank volume above the hollow body to such an extent that the liquid flows into the short piece of pipe of the hollow body, thereby filling said hollow body with a quantity of liquid being sufiiicient for some hundreds of developing and fixing procedures, and said bag, in non-inflated condition, unblocking the hole or opening the valve in the bottom of the hollow body and clearing the tank volume below the hollow body for the liquid flowing back through the open hole or valve and along the side-walls of the tank, until the level of liquid has reached again the level of the bottom of the hollow body.

References Cited by the Examiner UNITED STATES PATENTS 3,054,340 9/1962 Limberger 89 3,147,686 9/ 1964 Limberger 95-89 3,165,998 1/1965 Reick 95-89 NORTON ANSHER, Primary Examiner. 

